latest on that massive manhunt under way in colorado. The head of the state's prison systems gunned down on ace front doorstep in front of his wife. Abc's clayton sandell is in monument, colorado, with the very latest this morning. Good morning to you, clayton. Reporter: Good morning, josh. Right now hundreds of investigators are stepping up their manhunt for whoever came to this quiet neighborhood to the steps of the house right behind me to commit cold-blooded murder. This morning investigators trying to solve the murder of colorado prison official tom clements have few clues. One a dark-colored car in the neighborhood at the time of the shooting. They also want to find a woman speed-walking in the area who just might have seen the car and its driver. We have no suspect at this point and because we have no suspects we can't identify a motive. Reporter: Clements was at home with his wife tuesday night. He went to answer the front door and was suddenly shot in the chest. Somebody rang the doorbell. The husband answered and was shot. Reporter: Now police want to know if the man who oversaw thousands of inmates was possibly targeted for revenge. I kind of had it figured out right away sadly because i thought his position would leave him open. Reporter: A former warden at this prison says it's a career that creates enemies. You have 20,000 individuals. Anyone could have a reason to hurt mr. Clements. Reporter: Clements was murdered co-iincidentally the same day the governor of colorado signed tough measures for gun reform. Tom clements dedicated his life to being a public servant, making the world a better place and he is going to be deeply, deeply missed. Reporter: Now with no suspects police and officials here are on edge. This morning they have stepped up security both at the capitol and the governor's mansion. Josh. We'll have updates all morning long. For more we bring in former fbi special agent brad garrett. We heard for investigators the worst sort of case, a crime at this point without motive and without suspects. The murder of a top corrections official obviously very unusual but belief it could be related to a specific ruling that he made about a case just one week ago. At this point, brad, what are your thoughts here? Well, I don't know if you can jump to that conclusion. In other words, mr. Clements' position as director of the department of corrections could well have -- it may be a job-related homicide like your example, but just as relevant is the personal side of this clements. Is this something that has to do with another aspect of his life, his family's life and so investigators are stuck, i believe, at this point at looking at this very large circle. Did he know the person who arrived at his home that ultimately shot him? Was that a prearranged meeting and hopefully the police have figured that out at this point. So there's a lot of moving parts to this case, but it doesn't appear to be clear what component of his life maybe led to his death. You mentioned a personal aspect here. The murderer showing up on his doorstep to do what he did. In this case this may be the only thing they have to go on. Is there any sense of how to move the case forward? Well, the advantage you have is because he lives in an area that has some urban aspect to it so the shooter had to get from point a to point b. Is he on video someplace? Did he get captured by someone's home security system? Was he in a seven-11 before or after the shooting? This is one of the cases that the little bitty details of checking tapes, interviewing store clerks, all of that could lead to the resolution of this case. We can only hope progress is made today. Brad garrett, we thank you for your time this morning.

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